Air preheater



v Patente'd se 't. 11. 1928.

'UNITED STATES PATENT OFFICE.

GARL S. BEED, OIYONKERS, NEW YORK, ASSIGNOR TO INTERNATIONAL COMBUSTION ENGINEERING CORPOBATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

.AIR PREEEATER.

Application filed December 3, 1925. Serial No. 72,889.

This invcntion relates to air preheaters, and is particularly useful in connection with waste gas air preheaters, such as are used n pulverized ooal burning boiler installations.

In air preheatcrs of this character, the preheater is usually composed of a plurality of hollow platcs which extend within the ofl'- take 'for the waste products of combustion, the air being passed through' the hollow plates, and the waste gases passing over the hollow plates. Sometimes the leading edges of these plates deteriorate because of the heat, this being so particularly where .the amount of air being passed through the heater is relatively small, as might be the case, for example, when the boiler is being `operated for long periods of time at very low ratings.

The primary object of my invention is to overcome this difliculty.

The foregoing, together with such other objects as may hereinafter appear, or are incident to my invention, are realized by a construction which I have illustrated in a preferred form in'the accompanying drawings.

Fig. 1 is a section through a stack of a pulverized coal burning boiler installation showing the air preheater in side elevation, such air preheater embodying my improvements.

Fig. 2 is a fragmentary section taken on the line 2--2 of Fig. 1.

Referring now to the drawings, I have shown only those portions of the installation which are necessary to llustrate the character of my invention. The stack or other` ofitake is indicated at 7, and extending within the stack is the air preheater indicatcd, as a whole, by the reference character A. The

' air preheater consistsof a plurality of hollow platcs 8 through which the combustion air to be preheated is caused to flow in any preferred manner well under'stood in the art. The waste gases flow upwardly through the spaces between the plates. Obviousl the leading edges 8' of the plate will be su ject to the greatest heat, and may well deteriorate for the reasons above ponted out.

To overcome this, I weld or otherwise secure tubes 9 to the leading edges of the plates. These tubes are cooled, preferably by the circulation of water therethrough, although some other form of cooling medium may be leading ed es and the tubes 9 would be inclined, as s own, and the connection 12 would function as a downcomer from the boiler, and the connection 13 as an pcomer to the boiler. y

The advantages of my invention will be readily understood bythose skilled in the art.

What I claim is:

1. In combination, a waste gas conduit, a plurality of air conduits extending in said gas conduit comprising a plurality of hollow plates spaced to provide gas passage therebetween, a' manifold at each of two opposite sides of said gas conduit and outside thereof, a plurality of pipes connecting said conduits and located immediately in advance of the leading edges of said hollow plates, a cooling medium inlet to one of said manifolds and a cooling medium outlet from the other manifold.

2. In combination, a waste gas conduit, a pluralit of air conduits extending in said gas con uit comprising a plurality of hollow Iplates spaced to rovide gas assages thereetwecn, and ooo ing means or the leading edges of said air conduits comprising manifo ds outside thegas conduit, a plurality of pipes connecting said nanifolds and disposed immediately in advance of said edges, a. cooling medium inlet for one of said mani- 'folds, and a cooling medium outlet for the other manifold. y

In testimony whereof I have hereunto signed my name.

CARL I s. REED. 

